Can anyone give me any help with this? The carbs were sent to Piero for checking when I had other work done, so I know they are fine and the rest of the bike is standard but the top cylinder is fouling the plug, (dry, black, sooty).

I'm thinking I may have connected the Hoses from the carbs to the air boxes incorrectly?

Not currently near my vdue and got no pictures showing them on my laptop but think from memory the carb vac pipes go to their corresponding air box and the second connection on the LHS airbox is for the fuel overflow.

Mine was flooding the top cylinder when the sprag clutch was playing up. Bottom cylinder will drain into the exhaust. Thought it was a carb problem giving hydraulic lock on start up, but as I was correctly told by the fine people on this forum it needed a new sprag clutch.